Internal-combustion engine



Oef. 9, 1928. 1,686,794

.1. BRUGGER INTERNAL COIBUSTION ENGINE Filed Jan. 13, 1927 @EQ/Ww /u ATTO NEY Patented Oct. 9, 1928.

f UNITED STATES 30m' BBUGGER, 0F NEW YORK, N. Y.

INTEBNAL-COMBUSTION ENGINE.

Application 'illed January 13, 1927. Serial No. 160,812.

This invention relates to internal combustion engines, and broadly considered has for its primary object and purpose to provide in an engine of this type improved means for transmitting the power impulse of the exploded charge to the crankshaft whereby the dead center and the possibility of back firing is overcome and which will possess greater speed acceleration possibilities than engines of this type now generally employed for the propulsion of motor vehicles and other uses.

It is a more particular object of my invention is provide in each cylinder of the engine two pistons f one reciprocating within the other and having opposed heads at one of their ends providing a combustion chamber therebetween in which the charge is exploded to drive said pistons in relatively opposite directions, and power transmitting connections between said pistons. and separate crank arms projecting in relatively opposite directions from` the crankshaft center and out of radial alignment with each other.

It is also another object of the invention to provide each cylinder of the engine with means whereby-air is compressed in the upper end of theengine cylinder in the power stroke of one' of the istons and such compressed air being utilized for forcibly feeding the combustible gas mixture through the intake valve to the combustion chamber.

It is also a further general object of the invention to provide an internal combustion engine of the above character which is relatively simple in construction and arrangement of the mechanical parts thereof so that it will not be liable to get out of order or require frequent repair and may also be produced at comparatively small manufacturing cost.

With the above and other objects in view, the invention consists in the improved internal combustion engine and in the form, construction and relative arrangement of its several parts as will be hereinafter more fully described, illustrated in the accompanying drawings, and subsequently incorporated in the subjoined claims.

In' the drawing, lwherein I have illustrated one simple and practical embodiment of the combustion en 'ne illustrating one practical embodiment o my present improvements;

Fig. 2 is' a sectional view taken on the line 2 2 of Fig. 1, but showing the positions of -the relatively movable pistons at the end of the power stroke;

Fig. 3 is a horizontal sectional view taken substantially on the line 3-3 of Fig. 1, and

Fig. 4 is a diagrammatic view `illustrating the relative positions of the connecting rods between the pistons and the crankshaft with the pistons in the positions shown in Fig. 2 of the drawing.

Referring in detail to the drawing, 5 designates one of the engine cylinders having its upper portion surrounded by the usual water jacket 6 and fixed at its lower end upon a suitably formed crank case 7. These parts may be all of more or less conventional form, and it will be understood that any desired number of cylinders 5 may be cast en bloc, or in multiple. With each of the cylinders at one side thereof the manifold connection 8 is formed, said connection having an intake passage indicated at 9 and a similar exhaust passage shown at 10 in Fig. 3 of the drawings to which suitable intake and exhaust manifolds respectively, are adapted to be connected. Communication between these passages 9 and 10 and acommon port 11 leading to the interior of the cylinder 5 is controlled by the intake and exhaust valves 12 and 13 respectively. As herein shown, these valves are of the usual poppet type normally urged to their closed positions by suitable springs indicated at 14 and operated by the cam shaft 15. It will however, be understood that valves of the rotary sleeve type, or of other constructions as heretofore used in connection with internal combustion engines might be employed.

The upper end of the cylinder 5 is closed by the head 16 having an air inlet passage 17 and an air outlet paage 18 therein. In the outer ends of t ese passages, suitable valves 19 and 2O respectively are mounted, and preferably an approved type of air cleaner is associated with the inlet valve 19. The air outlet passage 18 is connected preferably by means of a iiexible pipe or conduit to the carburetor of the engine whereby preheated air under pressure is supplied to the carburetor to eect a more thorough vaporization of the liquid fuel and obtain a forcible feed` of the charge through the intake passage 9, as will be hereinafter more fully explained,

lVithin the cylinder 5, an outer comparatively long tubular piston 21 is slidingly fitted, said' piston being provided at spaced intervals in its outer .surface with the usual packing rings indicated at 22. At its upper end this piston is provided with the head 23 and at one side of the piston and extending downwardlv from 'this head 23 the longitudinally elongated intake and exhaust port 24 is formed through the wall of the piston and is in registering relation with the port 11 in the cylinder wall.

lVithin the tubular piston 21, a second relatively short piston 25 is reciprocatingly assembled and is likewise provided in its outer surface with the customary packing rings 26. The upper end of this piston is also formed with a head 27. Preferably the opposed surfaces of the piston heads 23 and 27 are concave. v

The crankshaft 28 is suitably journalled in bearings provided on the walls of the crank case 7. For each engine cylinder, this shaft is provided with the spaced crank arms 29 projecting in the same direction from the axis of the crankshaft. These crank arms are connected by the spaced connecting rods 30 with a wrist pin 31 extending diametrically through the lower end of the iston 21 and havingl its opposite ends suita ly mounted in the wall of said piston. The intermediate portion of this wrlst'pin is preferably' flattened orl of rectangular form as shown at 32. i 1,

The spaced crank arms 29 are connected by a third crank 33 which projects from the opposite side of the center of the crankshaft and is out of radial alignmentwith the cranks 29. Preferably this, crank 33 is offset from the crankshaft center with respectV to the cranks 429 about 30. The crank 33 is connected by a rod 34 with the wrist pin 35 of the inner tubular piston 25. This connecting rod 34 has a longitudinally extending openin in its intermediate portion' through which the attened central part 32 of the wrist pin 31 extends, and permits of the angular movement of said co'nnecting rod 34 relative to said wrist pin.

As shown in Fig.` 1 of the drawings, the

two pistons 21 and 25 have compressed the charge admitted through the intake valve 12 and through the port 11 between their opposed heads 23 and 27 and the crank 33 of the shaft 28 is approximately at the upper dead. center position while the cranks 29 have passed the lower dead center position on their upward movement, at the left thereof as indicated by the arrow in the drawing. When the circuit of the spark plug shown at 36 is now closed through the ignition system, the compressed gas is ignited and the pressure of the exploded charge is exerted substantially equally in opposite directions against the opposed piston heads 23 and 27 so that the outer piston is moved upwardly while the inner piston is moved downwardly. This results in the continued upward movement of the cranks 29, thereby moving the crank 33 beyond the dead center position shown in Fig. 1. It will therefore, be apparent that it is impossible for the explosion to take place before the crank 33 has reached the dead center position and that owing to the relative angular arrangementof the cranks29 and 33, the thrust of one or the other of the pistons will be transmitted to the crankshaft in angular relation to the upper or lower dead center positions.

In Fig, 4 of the drawings, I have shown the pistons at the end of the power stroke and the cranks 29 vand 33 therefor in the opposite relation to the crankshaft center from that shown in Fig. 1. From reference thereto, it will be observed that the connection of the rod 34 of the inner piston with the crank 33 is now approximately atv the lower dead center position while theI crank connections 29 to the outer piston are disposed at the right of the upper dead center position.

/It will also be noted that by the provision of the two pistons reciprocating ink relatively opposite directions to transmit the power impulse to the crankshaft, I am enabled to shorten the piston stroke and correspondingly shorten the length of the cranks and reduce the angular movement of the connecting rods 30 and 34. Thus, better acceleration from the lower to the higher speeds is possible than can be obtained in the use of the usual single piston in'each cylinder. f

After the power stroke, in the following upward movement of the inner piston and the downward movement of the outer piston, thc burned gases are expelled, it being understood that the exhaust valve 13 is open during the initial part of this movement of the pistons. As the pistons again approach the position as seen in Fig. 1, the exhaust valve closes and the intake valve is opened so that a fresh charge is admitted to the combustion space between the piston heads. f Thereafter the charge is exploded and the above described cycle is repeated.

In the downward movement of the outer piston to the position of Fig. 1, air is drawn into the upper end of the cylinder 5 through the valve 19, and inthe subsequent upward power stroke of this outer piston, the air is compressed in the upper end of said cylinder until the spring-held valve 20 1s overcome, when the air is expelled under pressure through the conduit connectlonto the carburetor. SinceV the wall of the cylinder 5 becomes more or less highly heated from the exploded gases, it 1s apparent that this air Which is compressed in the upper end of the cylinder will absorb a certain proportion of such heat. Therefore as heretofore explained, such preheated coinpressed air admitted to the carlniretor will produce better Yaporization of the liquid fuel and likewise constitute means for conveyinp the vaporized fuel under pressure to port ll as well as fur `L:hinathe desired volume of oxygen for insuring proper conduistion of the mixture,

From the foregoing desf'ription considered in connection with the accompanying;r drawinggj` it will be seen that I have devised a very simple and novel type of internal combustion engine whereby the dead center position of the crankshaft is effectively overcome and the possibility of back tiring due to pre-ignition of the combustible charge is obviated. Also, due to the transmission of the thrust to the crankshaft by pistons moving in relatively opposite directions and thereby shortening` the stroke` `greater freedom from vibration and acceleration of the speed more quickly than has heretofore been possible may he realized. It will also be noted that the construction and arrangement of the two 'pistons and their connections with the crankshaft are of relatively simple mechanical torni so that they will function in a positive andy reliable manner and are not subject to excessive strain or lil-(ely to require more or less frequent repair.

I have herein shown a practical embodiment of my present inprovements which I believe to he best adapted for the intended purposel` but it will nevertheless be understood that the essential features thereof are also susceptible of embodiment in various other alternative structural forms. and I accordingly reserve the privilege of resortingr to all such legitimate changes in the form, construction and relative arrangement of the various detail parts as may be fairly eniliodied within the spirit and scope of the invention as claimed.

I claim:

cylinder, two pistons in said cylinder reciprocating one Within the other and having spaced heads forming a combustion chamber therebetween, a power shaft having spaced cranks projecting from one side of its axis and a third crank between said spaced cranks projecting upon the opposite side of the shaft axis and out of radial alignment with said first named cranks, a pair of rods connected at one of their ends with said first named cranks, a wrist pin connection between the other ends of said rods and the lower end of the outer piston` a relatively long' rod directly connected at one end with said last named crank, and a wrist pin connecting the other end of said latter rod with the inner pistonv` said wrist pins being located in intersecting relation to the central axial line of the pistons, and said latter rod havingy ay longitudinally extending opening :accommodating the first named wrist pin to permit of the relative angular movement of said connecting rod.

2. In an internal combustion engine, a cylinder, two pistons in said cylinder reciprocating one within the other and having opposed heads forming a combustion chamber therebetween, a power shaft having a pair of cranks projecting from one side of its axis and a third crank projecting upon the opposite side ot the shaft axis, a single connecting' rod directly connecting` the latter crank with the inner piston, a pair of connecting rods respectively connected at one of their ends with the iirst named cranks and having their other ends positioned within the lower end of the outer piston. a Wrist pin L;-onnectin .fgf said ends of the latter connecting rods with the outer piston and ex tendine` diametrically across said piston` and the connectingr rod between the inner piston and the shaft crank being provided with means positioned with respect to said wrist pin 'to permit of the angular movement of said connecting rod relative thereto.

In testimony that I claim the foregoingr as my invention. I have signed mv name hereto.

JOHN ERUGGER. 

